Solar cells (also known as photovoltaic cells) convert light into electrical energy. In general, a solar cell has a photoelectric conversion layer that, upon exposure to light, generates charge carriers, such as electrons. Electrodes in the solar cell conduct these electrons to an external device, thereby producing an electrical current.
One common solar cell technology collects the charge carriers by forming a plurality of electrically conductive fingers on the photoelectric conversion layer. These fingers conduct the collected charge carriers to a bus bar, which has a large surface for electrically connecting the fingers to an external device. In general, the electrically conductive fingers and the bus bar form an electrode on the photoelectric conversion layer.
Typically, electrodes in a solar cell are electrically connected to the electrodes in other solar cells to form a solar module. These electrically connections are ordinarily achieved by using a soldering process to attach ribbons (e.g., flat copper wires) to the electrodes of a solar cell.